Cutting Steel

by Albin Drzewianowski

One of the first things you learn as a beginning blacksmith is that you usually have to cut the steel before you can forge it. You have a number of options available to you; which ones you choose will depend on what type of steel you are cutting, your wallet, and space available for the tool.

Hardy Tool - One of the simplest and most basic cutting tools is the hardy tool which is used in the hardy hole of the anvil. Ideally you should have 3: 2 hot cuts and 1 cold cut. The difference between a hot cut and cold cut is the angle of the chisel edge. For cold cutting you need a more blunt angle, usually about 60 degrees and it will be bevelled on both sides. Because you are cutting cold, you need to support the cutting edge. For a hot cut you can get away with about 30 degrees. Because the steel is red hot, it is softer and a smaller angle will cut faster and deeper. One of the hot cuts should be beveled on both sides, like a knife. This will put a "V" shaped groove in the steel and both cut edges will have an angle to them. The second type of hot cut, ofter called a "butcher" will be beveled only on one side, like a wood chisel. This type of hot cut leaves one cut edge at an angle and the other perpendicular.

Now we have to take into account what type of steel you are cutting. If you are hot cutting, it really doesn't matter. High carbon steel/alloy steel all cut when red hot. Your cold cut hardy should only be used on mild or low carbon steel.

You can also cut steel with hand held or handled chisels. the same rules apply as for an anvil hardy. The anvil hardy is really just a chisel that fits into the anvil.

Hacksaw - When it comes to cutting mild steel, I went a long time with a hacksaw. I cut some fairly thick steel with a hacksaw; took a while, but you just plow your way through. A few tips on using a hacksaw. Spend a few extra dollars and get a high tension hacksaw frame. In my opinion, they really make a difference. Just remember, after done cutting, back off the tension. Also, again, pay the extra money and buy good quality bi-metal blades. They last so much longer than the cheap blades. Remember you should have at least 3 teeth always in contact with the metal. So when cutting thin stock, you need a blade with more teeth per inch. Finally, remember to lift the saw on the back stroke, don't drag the teeth on the steel, it only dulls the blade.

Swivel Head Metal Cutting Bandsaw - Again, for mild steel, this tool will cut alot of steel. The "swivel head" in the name means that you clamp the work down and pull the bandsaw over and the weight of the top half of the bandsaw provides the pressure for the cut. You can leave one of these un-attended as it is cutting. When it is through cutting, it will shut itself off. You see these in Harbor Freight starting at about $200. Again, pay for the better bi-metal blades they last significantly longer. When cutting larger stock, I keep a spray can of WD40 next to the saw and give the blade a shot of the WD40 every once in a while to act as a lubricant. The higher quality units have lubricant/cooling mechanisms as part of the saw. This saw can be used in an up-right position and then you can hand feed the stock, doing curves, following lines, etc. The down side of this machine is that it takes up about 8 square feet of floor space.

* Bandsaw in the upright postion:

* Bandsaw in the down position:

Hand held Portable Bandsaw - Porter Cable (and probably other manufacturers) make a hand held electric bandsaw. They run about $375. The advantage is that it does not take up much space and you can bring it with you to hammer-ins, demos, etc. The down side is that you have to hold the tool as it cuts, and this is a fairly heavy tool, I am guessing over 20 pounds. Also, the accuracy of the cut will depend upon you. It is possible to rig the bandsaw so that it is held by your vice. Also, they sell stands which allow this bandsaw to operate like a chopsaw, but now it is taking up bench space.

Chopsaw - This cutting tool uses a very thin abrasive disc to grind its way through the steel. This is a bench top tool. It only cuts a straight line, although the vice will allow you to clamp your stock at any angle to the blade. The big strength of the this tool, is in cutting alloy and high carbon steel. The down sides are that it makes a real mess, abrasive powder, throws sparks - possible fire hazard, and will definitely effect any temper in the steel. But when you have a jackhammer bit or peice of H13, this is about the only thing that will cut them.

* Chopsaw:

4 inch Angle Grinder - You can get abrasive cut off disks that will fit your 4 inch angle grinder. This in effect gives you a hand held chop saw. They work fairly well. The trick is to keep the blade straight in the cut. If you don't keep it perfectly straight the disk will bind and shatter.

Next we get into some of the more esoteric cutting systems

Oxy-acetylene Torch - This will cut through a lot of different types and sizes of steel. But the cut is pretty jagged and each end of the cut will have to be ground back, as the torch actually cuts by burning its way through the steel and this damages the steel adjacent to the cut.

Plasma Cutter, Water Jet Cutter - Very high tech and very expensive. Best to hire this type of work out to someone who already owns this type of equipment and knowws how to use it.

Safety - With all of these cutting tools, ALWAYS DRESS THE CUT ENDS . Each tool leaves a burr. The chop saw in particular leaves a large razor sharp burr. Removing the burr will prevent a possibly nasty accident. Also, especially with the chop saw, the cut ends will be hot enough to burn you, rememember the cut is made by the blade grinding its way through. Furthermore, with the chop saw be sure to use good eye protection, preferably a full face shield; even standing in front of the saw you get abrasive grit thrown at you.

-- RebStaup - 24 Jan 2008